ABSTRACT
All bee species, be they solitary or social, provision their broods by central place foraging, which means they gather pollen and nectar from owers and use them to provision a nest. The foraging range of bees is thus a fundamental aspect of their ecology, for it determines the area of the habitat that an individual can exploit (Bronstein 1995; Westrich 1996). Understanding the spatial relationship between nest and food resources allows us to make predictions about colony survival and distribution (Nakamura and Toquenaga 2002; Williams and Kremen 2007). Also, if we are to study the effects of habitat management on bee reproduction (i.e., nest success), the appropriate scale of experimental plots depends on the area over which the occupants of each nest forage (whether it is a single bee or a large group of workers). Similarly, if we are to manage habitats to conserve particular bee species, their foraging range inuences the distribution of forage that is considered optimal. For bees to thrive, presumably their nest sites and forage sites must be sufciently close together that they can economically visit the forage. In the case of social species such as bumble bees with a nest that may persist for many months, the nest must be within foraging range of suitable owers throughout its life. Bee foraging ranges are also important in the consideration of insect-mediated crop pollination. The distance a bee ies will determine which elds are visited within the vicinity of the nest, and also the distances over which pollen might be carried to effect gene ow within and between elds (Damgaard et al. 2008). This is particularly relevant when crops are grown for high seed purity, or when genetically modied crops are grown and the transfer of pollen between
Introduction ......................................................................................................................................97 Measuring Bumble Bee Foraging Range .........................................................................................98
